Question

1. choose the best answer.

a list of elements that are ranked in decreasing order based on their reactivity is a(n) _____.
○ reactive series
○ activity series
○ element series
○ electronegativity series

1. choose the best answer.

identify the two cations that swap in the following chemical equation:
2ag + h₂s → ag₂s + h₂
□ s²⁻
□ ag¹⁺
□ h¹⁺
□ h₂

Explanation:

Sub - Question 1

The question is about a list of elements ranked by reactivity. The activity series (also known as the reactivity series) is a list of metals (and sometimes non - metals) ranked in order of decreasing reactivity. "Reactive series" is not the standard term, "element series" is too general, and "electronegativity series" ranks elements by electronegativity (a different property related to electron attraction, not reactivity in the context of chemical reactions like displacement). So the correct term is activity series.

In the chemical equation \(2\text{Ag}+\text{H}_2\text{S}\to\text{Ag}_2\text{S}+\text{H}_2\), we first identify the ions. In \(\text{H}_2\text{S}\), the cation is \(\text{H}^{1 +}\) (since \(\text{S}^{2-}\) is the anion). Silver (Ag) is initially in elemental form (neutral), but in the product \(\text{Ag}_2\text{S}\), it is in the form of \(\text{Ag}^{1+}\) cation. The reaction involves a single - displacement reaction where Ag (which will form \(\text{Ag}^{1+}\)) and \(\text{H}^{1+}\) (from \(\text{H}_2\text{S}\)) are the cations that swap. \(\text{S}^{2-}\) is an anion, and \(\text{H}_2\) is a neutral molecule, not a cation.

Answer:

B. activity series

Sub - Question 2